1. Field of the Disclosure
Embodiments disclosed herein relate generally to downhole tools. In particular, embodiments disclosed herein relate to a pressurizing device having a ball drop module for pressure activating downhole tools.
2. Background Art
In oilfield drilling and completion, various downhole tools in a drillstring may be pressure activated by increasing a pressure in a central bore of the drillstring. To increase the pressure in the central bore, fluid flow through the central bore may be blocked or obstructed at a particular location in the bore, which allows fluid pressure to increase above the obstruction in the bore. Ball drop devices are one such tool that may be used to obstruct the central bore by dropping a steel ball into the central bore and allowing the drilling fluid or similar liquid to carry the ball, assisted by gravity down the hole until the ball lodges in a landing seat located downhole in the bore. The dropped ball may obstruct the fluid flow through the central bore and allow the fluid pressure uphole of the ball to be increased. When activation of a particular tool is complete, the ball may be removed from the central bore, which allows fluid flow to resume through the central bore.
Removal of the ball from the central bore may be carried out in a number of ways. For example, the ball may be made of a drillable material, such that the ball is drilled through to allow the fluid to return to flow through the central bore. Alternatively, the landing seat or ball may be formed of a material such that the ball may be extruded through the seat at a high pressure to remove the ball. However, extrusion or drilling through the ball leaves a reduced diameter section of the central bore at the landing seat location (i.e., the diameter of the central bore is reduced to a diameter of the landing seat orifice). This reduced diameter may prevent additional tools from being passed through to locations downhole of the landing seat.
To reopen the central bore to its original diameter, release mechanisms have been incorporated into the landing seat to allow both the ball and the landing seat to be moved. For example, one such mechanism includes a landing seat having a collet finger mechanism to secure the landing seat in the bore, the collet fingers then being disengaged and the ball and seat forced downhole. However, the collet finger mechanism has proved to be difficult to position and seal properly in the bore, does not provide the ability to reliably activate the downhole tool, and often does not fail predictably when required. Further, the above mentioned mechanisms are not capable of being reused and instead are discarded and lost at a bottom of the wellbore after use.
Accordingly, there exists a need for a reusable ball drop device that may be reliably operated for activation of downhole tools.